adjectiveEtymology: Middle English, from Late Latin sempiternalis, from Latin sempiternus, from semper ever, always, from sem- one, same (akin to Old Norse samr same) + per through — more at same, forDate: 15th century
of never-ending duration ;eternal
• sempiternallyadverb

sempiternal — adjective /ˌsɛm.pɪˈtəː.nəl,ˌsɛm.pɪˈtɝ.nəl/ a) Seemingly everlasting or eternal. The one thing which we seek with insatiable desire is to lose our sempiternal memory and to do something without knowing how or why; in short to draw a new circle. b) … Wiktionary